In recent years, technology has been proposed by which a computer performs centralized control of packet forwarding by communication equipment such as a switch or router.
Patent Literature (PTL) 1 discloses technology in which switches in a communication system process packets in accordance with an instruction notified by a control apparatus. The control apparatus performs centralized control of a plurality of switches in the communication system.
Non Patent Literature (NPL) 1 discloses technology in which a plurality of control apparatuses share control of a plurality of switches in a communication system.    [PTL 1]    International Publication No. 2008/095010